JsonUtility with openweatherAPI

Here’s my JSON API in:

http://api.openweathermap.org/data/2.5/weather?q=Vietnam,vn&appid=0ab6a57ce5d39ea31b0ecd53db35edf4&mode=json&lang=en

{
    coord: {
    lon: 105.85,
    lat: 21.03
    },
    weather: [
    {
    id: 800,
    main: "Clear",
    description: "clear sky",
    icon: "01n"
    }
    ],
    base: "stations",
    main: {
    temp: 297.897,
    pressure: 1009.91,
    humidity: 92,
    temp_min: 297.897,
    temp_max: 297.897,
    sea_level: 1018.33,
    grnd_level: 1009.91
    },
    wind: {
    speed: 1.93,
    deg: 181.501
    },
    clouds: {
    all: 0
    },
    dt: 1469311176,
    sys: {
    message: 0.0124,
    country: "VN",
    sunrise: 1469226442,
    sunset: 1469273919
    },
    id: 1561096,
    name: "Xóm Pho",
    cod: 200
    }

Here’s my classes:

WeatherData.cs

[System.Serializable]
public class WeatherData {
    public Coord cord;

    public Weather[] weather;

    public string @base;

    public Main main;

    public Wind wind;

    public Clouds clouds;

    public uint dt;

    public Sys sys;

    public int id;

    public string name;

    public int cod;

    public void Load(string savedData)
    {
        JsonUtility.FromJsonOverwrite(savedData, this);
    }
}

Coord.cs

[System.Serializable]
public class Coord
{
    public float lon;
    public float lat;
}

Other classes (Weather, Base, Main …) worked fine. But when serialized Coord object, value of lon and lat not correct (lon = lat = 0.0f).
Can somebody explain me why?

Well:

cord != coord

You named your variable wrong.